Middle Gear overhall

[gleno]

Upon removal of the middle gear side cover I've discovered the cause of a noise in the gear box. I recovered a piece of a broken gear tooth from either the middle drive shaft gear or the middle pinion gear.

So now it's time to get into the guts of this engine.

I would appreciate a quick how to from those in the forum who have tackled this job before. Do I have to completely disassemble the motor or is there a smarter way to go about it?

 

[davesax36]

You can pull the gear for the drive shaft without pulling the motor, but if you need to get in, it's gonna have to come out. I don't think dropping the oil pan will get you where you need to be, either. Did you have any other gear issues (slipping out, etc)?

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[Rusty McNeil]

If you pull the output shaft/yoke as mentioned it will let you determine if either it has a broken tooth or look inside and with the bike in neutral you can rotate the tranny shaft and inspect that gear for broken teeth.
If its just the output shaft gear you might could replace just it, observing the procedure for setting lash. (Its in the book and on Damon's
Video)
I will say I think they probably are supposed to be replaced in a set (not sure) but you might get away with an easy fix.

If its the gear up inside the case you'll have to pull the engine for sure, which would be a good time to send the tranny to Sean for an inspection, repair and maybe an undercut.

If you have to go inside the engine I highly recommend Damon's video. Its worth it.

A friend of mine had the same issue with a PCW 1500, they let the wafer shim on the second tranny shaft end up not in its proper place when putting the case halves together leading to too much gear lash and ultimately middle gear failure.
It was making a thrumming humming noise that progressed to a soft clicking.

He had it out replaced and back in with about two days time labor.

 

[one2dmax]

The transmission and worm gear (middle gear) set requires splitting the case (though heads/cams and even valve covers don't have to be removed). IF you are only having damage to the output gear section of the gear (with the ujoint bolted to it) then you could try swapping just that part out first and see what it does. Might save a ton of work and only have a little more drivetrain whine.

 

[gleno]

Can some one tell me where to find 'Damon's Video' ?

 

[gleno]

Found it.

 

[wildweasel_pt]

I replaced a middle gear output shaft due a pinion shear once, used the same shims and it works the same since. The lash was about the same and the bike wasn't worth replacing the full set of gears.